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Articles 1 - 19 of 19

Full-Text Articles in Social and Behavioral Sciences

A Classification Of Intersection Type Systems, Martin W. Bunder Jan 2002

A Classification Of Intersection Type Systems, Martin W. Bunder

Faculty of Engineering and Information Sciences - Papers: Part A

The first system of intersection types. Coppo and Dezani [3], extended simple types to include intersections and added intersection introduction and elimination rules ((ΛI ) and (ΛE) ) to the type assignment system. The major advantage of these new types was that they were invariant under β-equality, later work by Barendregt, Coppo and Dezani [1], extended this to include an (η) rule which gave types invariant under βη-reduction.

Urzyczyn proved in [6] that for both these systems it is undecidable whether a given intersection type is empty. Kurata and Takahashi however have shown in [5] that this emptiness ...


A Sub-Vector Weighting Scheme For Image Retrieval With Relevance Feedback, Lei Wang, Kap Luk Chan, Xuejian Xiong Jan 2002

A Sub-Vector Weighting Scheme For Image Retrieval With Relevance Feedback, Lei Wang, Kap Luk Chan, Xuejian Xiong

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a sub-vector weighting scheme is proposed for the case of small sample in image retrieval with relevance feedback. By partitioning a multi-dimensional visual feature vector to multiple sub-vectors, the singularity problem caused by small sample can be avoided by the lower dimensionality of the sub-vectors. Then the optimal weighting can be performed on these sub-vectors respectively and the similarity scores obtained are combined as the final score to rank the database images. Experimental results demonstrated that the proposed weighting scheme can significantly improve the efficacy of image retrieval with relevance feedback.


The Dual Reciprocity Boundary Element Method For Magnetohydrodynamic Channel Flows, Song-Ping Zhu, Huan-Wen Liu Jan 2002

The Dual Reciprocity Boundary Element Method For Magnetohydrodynamic Channel Flows, Song-Ping Zhu, Huan-Wen Liu

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we consider the problem of the steady-state fully developed magnetohydrodynamic (MHD) flow of a conducting fluid through a channel with arbitrary wall conductivity in the presence of a transverse external magnetic field with various inclined angles. The coupled governing equations for both axial velocity and induced magnetic field are firstly transformed into decoupled Poisson-type equations with coupled boundary conditions. Then the dual reciprocity boundary element method (DRBEM) [20] is used to solve the Poisson-type equations. As testing examples, flows in channels of three different cross-sections, rectangular, circular and triangular, are calculated. It is shown that solutions obtained ...


Learning Kernel Parameters By Using Class Separability Measure, Lei Wang, Kap Luk Chan Jan 2002

Learning Kernel Parameters By Using Class Separability Measure, Lei Wang, Kap Luk Chan

Faculty of Engineering and Information Sciences - Papers: Part A

Learning kernel parameters is important for kernel based methods because these parameters have significant impact on the generalization abilities of these methods. Besides the methods of Cross-Validation and Leave-One-Out, minimizing some upper bounds on the generalization error, such as the radius-margin bound, was also proposed to more efficiently learn the optimal kernel parameters. In this paper, a class separability criterion is proposed for learning kernel parameters. The optimal kernel parameters are regarded as those that can maximize the class separability in the induced feature space. With this criterion, learning the kernel parameters in SVM can avoid solving the quadratic programming ...


An Image Database Semantically Structured Based On Automatic Image Annotation For Content-Based Image Retrieval, Xuejian Xiong, Kap Luk Chan, Lei Wang Jan 2002

An Image Database Semantically Structured Based On Automatic Image Annotation For Content-Based Image Retrieval, Xuejian Xiong, Kap Luk Chan, Lei Wang

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we presented a semantically structured image database for content-based image retrieval. A class descriptor is proposed to represent each class using a multiprototype model, which can be obtained by using a learning scheme, such as the Unsupervised Optimal Fuzzy Clustering algorithm, on a group of sample images manually selected from the class. Based on the proposed Image-Class Matching Distance, a similarity measure at the semantic level between an image and classes, images can be annotated by tokens of classes. Hence, composite features of images, including low-level descriptors, class descriptors, and image annotation, are stored into a structured ...


Limitations Of Current Design Procedures For Steel Members In Space Frames, Lip H. Teh Jan 2002

Limitations Of Current Design Procedures For Steel Members In Space Frames, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

The use of more advanced methods of analysis to design steel frames may lead to substantial material savings, in addition to simplicity in the design procedures. However, these benefits do not yet appear to be a powerful incentive for many structural engineers to abandon the familiar linear elastic analysis (LEA) based design procedures, even when dealing with steel structures that are not regular rectangular frames. This paper uses a heuristic example to demonstrate the serious limitations of the LEA based design procedures, whether alignment charts or system buckling analysis is used to determine the effective lengths of the compression members ...


A Distribution-Based Face/Nonface Classification Technique, Son Lam Phung, Douglas Chai, Abdesselam Bouzerdoum Jan 2002

A Distribution-Based Face/Nonface Classification Technique, Son Lam Phung, Douglas Chai, Abdesselam Bouzerdoum

Faculty of Engineering and Information Sciences - Papers: Part A

The core element of many existing approaches to face detection is the classification algorithm that determines if a sub-image of an input image contains a face pattern. In this paper, we present a novel and effective distribution-based face/non-face classification technique that detects frontal face patterns with possible in-plane rotation. A 15x15 input sub-image is first processed by a color filter, which verifies the presence of human skin color in the sub-image. Then, the intensity image is extracted from the identified skin color sub-image and converted into a vector in a high-dimensional space (R225). Principal component analysis is employed ...


Mechanically Alloyed Amorphous Ti50(Cu0.45ni0.55)44-X Alxsi4b2 Alloys With Supercooled Liquid Region, L C. Zhang, Jian Xu, E Ma Jan 2002

Mechanically Alloyed Amorphous Ti50(Cu0.45ni0.55)44-X Alxsi4b2 Alloys With Supercooled Liquid Region, L C. Zhang, Jian Xu, E Ma

Faculty of Engineering and Information Sciences - Papers: Part A

A high-energy ball milling procedure has been developed to produce amorphous alloys in Ti50(Cu0.45Ni0.55)44−xAlxSi4B2 (x= 0, 4, 8, 12) powder mixtures. The milling products were characterized using x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The Ti-based amorphous alloy powders prepared through this solid-state process exhibit a well-defined glass transition and a supercooled liquid region (ΔTx =64 K) close to the largest achieved so far for Ti-based undercooled melts. The substitution of Al for Cu and Ni has beneficial effects on stabilizing ...


Equity Issues In E-Education, Penelope Mcfarlane, Anne Fuller Jan 2002

Equity Issues In E-Education, Penelope Mcfarlane, Anne Fuller

Faculty of Engineering and Information Sciences - Papers: Part A

The potential of the World Wide Web as a medium for course delivery was early recognized, and universities were quick to take advantage of its possibilities for reaching a wider and more diverse student population. As the amount of course content being offered online increases, both to internal and external students, universities are increasingly exposed to the possibility that students may claim they are disadvantaged by either the mode of delivery or, in the case of overseas students, the content itself. In this paper we review the explosion in internet-based delivery of courses and discuss the areas where we believe ...


Why Don't We Teach Software Engineers About The Law?, Anne Fuller, Peter Croll Jan 2002

Why Don't We Teach Software Engineers About The Law?, Anne Fuller, Peter Croll

Faculty of Engineering and Information Sciences - Papers: Part A

Much work has been done in recent years developing software engineering curricula. SE research has traditionally focused on the needs of very large corporations undertaking equally mammoth and complex development projects, consequently, current curricula tend to focus on this model. Yet by far the majority of software development is undertaken by Small to Medium Enterprises. The rise of the internet as a platform for commercial applications has partly driven this move away from monolithic software development. Depending on the nature of the application itself many of these products can be described as 'critical' with the failure of such a product ...


Design And Implementation Of A Content Filtering Firewall, Rongbo Du, Rei Safavi-Naini, Willy Susilo Jan 2002

Design And Implementation Of A Content Filtering Firewall, Rongbo Du, Rei Safavi-Naini, Willy Susilo

Faculty of Engineering and Information Sciences - Papers: Part A

A firewall is a system for enforcing access control policy between two networks and is one of the most important measures to protect against network attacks. Firewalls traditionally protect the internal network from outside threats. But there has been increasing need for preventing the misuses of the network by the internal users which most previous firewalls overlook. In this paper, we propose a method of adding content filtering functionality to the firewall and describe its implementation. We also show a new attack that combines JAVA Applet and XML to get around the content filtering firewall, hence showing the need for ...


The Two-Prime Analogue Of The Hecke C*-Algebra Of Bost And Connes, Nadia Larsen, Ian Putnam, Iain Raeburn Jan 2002

The Two-Prime Analogue Of The Hecke C*-Algebra Of Bost And Connes, Nadia Larsen, Ian Putnam, Iain Raeburn

Faculty of Engineering and Information Sciences - Papers: Part A

Let p and q be distinct odd primes. We analyse a semigroup crossed product C * (G p,q) α 2 similar to the semigroup crossed product which models the Hecke C * -algebra of Bost and Connes. We describe a composition series of ideals in C * (G p,q) α 2 , and show that the structure of one of the subquotients reflects interesting number-theoretic information about the multiplicative orders of q in the rings Z/pl Z.


Regularity Of Induced Representations And A Theorem Of Quigg And Speilberg, Astrid An Huef, Iain Raeburn Jan 2002

Regularity Of Induced Representations And A Theorem Of Quigg And Speilberg, Astrid An Huef, Iain Raeburn

Faculty of Engineering and Information Sciences - Papers: Part A

Mackey's imprimitivity theorem characterizes the unitary representations of a locally compact group G which have been induced from representations of a closed subgroup K; Rieffel's influential reformulation says that the group C*-algebra C*(K) is Morita equivalent to the crossed product C0(G/KG [14]. There have since been many important generalizations of this theorem, especially by Rieffel [15, 16] and by Green [3, 4]. These are all special cases of the symmetric imprimitivity theorem of [11], which gives a Morita equivalence between two crossed products of induced C*-algebras.


Mr Damper And Its Application For Semi-Active Control Of Vehicle Suspension System, G Z. Yao, F F. Yap, G Chen, Weihua Li, S H. Yeo Jan 2002

Mr Damper And Its Application For Semi-Active Control Of Vehicle Suspension System, G Z. Yao, F F. Yap, G Chen, Weihua Li, S H. Yeo

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, a semi-active control of vehicle suspension system with magnetorheological (MR) damper is presented. At first a MR damper working in flow mode is designed. Performance testing is done for this damper with INSTRON machine. Then a mathematical model, Bouc–Wen model, is adopted to characterize the performance of the MR damper. With optimization method in MATLAB® and experimental results of MR damper, the coefficients of the model are determined. Finally, a scaled quarter car model is set up including the model of the MR damper and a semi-active control strategy is adopted to control the vibration of ...


An Improved Hardy-Sobolev Inequality And Its Application, Adi Adimurthi, Nirmalendu Chaudhuri, Mythily Ramaswamy Jan 2002

An Improved Hardy-Sobolev Inequality And Its Application, Adi Adimurthi, Nirmalendu Chaudhuri, Mythily Ramaswamy

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


Product Systems Over Right-Angled Artin Semigroups, Neal J. Fowler, Aidan Sims Jan 2002

Product Systems Over Right-Angled Artin Semigroups, Neal J. Fowler, Aidan Sims

Faculty of Engineering and Information Sciences - Papers: Part A

We build upon MacLane's definition of a tensor category to introduce the concept of a product system that takes values in a tensor groupoid G. We show that the existing notions of product systems fit into our categorical framework, as do the k-graphs of Kumjian and Pask. We then specialize to product systems over right-angled Artin semigroups; these are semigroups that interpolate between free semigroups and free abelian semigroups. For such a semigroup we characterize all product systems which take values in a given tensor groupoid G. In particular, we obtain necessary and sufficient conditions under which a collection ...


Numerical Investigation Of A Reaction In A Batch Reactor: Flammability Limits, M. J Sexton, Harvinder Sidhu, Mark Nelson Jan 2002

Numerical Investigation Of A Reaction In A Batch Reactor: Flammability Limits, M. J Sexton, Harvinder Sidhu, Mark Nelson

Faculty of Engineering and Information Sciences - Papers: Part A

We study the spatial behaviour of the hydrogen-chlorine reaction in a batch reactor. The solutions exhibit regimes of slow and fast reaction. The main aim of this work is to distinguish between flaming and non-flaming mixtures from the numerical solutions. After setting out a practical criterion for flammability, we construct diagrams in parameter space which display the regions in which the reaction mixture is flammable.


A 2-Secure Code With Efficient Tracing Algorithm, Joseph Tonien, Rei Safavi-Naini, Yejing Wang Jan 2002

A 2-Secure Code With Efficient Tracing Algorithm, Joseph Tonien, Rei Safavi-Naini, Yejing Wang

Faculty of Engineering and Information Sciences - Papers: Part A

No abstract provided.


Mtd Method For Better Prediction Of Sea Surface Temperature, Velappa Ganapathy, K Meena, Kashem M. Muttaqi Jan 2002

Mtd Method For Better Prediction Of Sea Surface Temperature, Velappa Ganapathy, K Meena, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

A class of incremental learning procedures known as the Modified Temporal Difference (MTD) method is introduced in this paper for fixed-step prediction problems which uses the functional features of Multilayer Perceptron. The method is applied for weekly prediction of the Sea Surface Temperature (SST) from oceanographic data. Temporal Difference (TD) methods suggest how each output of a temporal sequence must be changed, whereas a back-propagation algorithm decides which part(s) of a network to change in order to influence its output and reduce the overall error. In other words, TD methods and back-propagation address temporal credit and structural credit assignment ...